Next generation systems are expected to support a wide range of use cases with varying requirements ranging from fully mobile devices to stationary Internet of Things (IoT) or fixed wireless broadband devices. The traffic pattern associated with many use cases is expected to consist of short or long bursts of data traffic with varying length of waiting period in between (also referred to as an “inactive state”). For such traffic it is important to both optimize the inactive state between the data bursts as well as the transition to an active state. The signaling related to inactive devices should be minimized by having relaxed requirements on mobility tracking in inactive state, while the state transition can be optimized by keeping and re-using the device context when the device returns. At the same time it is also important to minimize the UE battery consumption both in active and inactive state.
Conventionally, paging is bundled with TA information. For instance, in Long Term Evolution (LTE) systems, TA is a concept defined in Core Network (CN). Once a terminal device, for example, user equipment (UE), attaches to Mobile Management Entity (MME), it knows the TA information assigned by the MME and then knows when and how to report its location to the MME via Tracking Area Update procedure, included in a Non-access Stratum (NAS) message.
Since TA information is managed in the CN, a device in an accessing network (also referred to as a “network device”) does not know all the possible locations of a UE. When there is a task of paging in an accessing network, for example, Radio Access Network (RAN), the network device can only page the UE within its managed cells. However, broadcasting paging from the access network will incur both long delay and unnecessary overhead.